Question

Match the elements of table I and II.

Table I	Table II
a) Myopia	i) Bifocal len
b) Hypermetropia	ii) Cylindrical lens
c) Presbyopia	iii) Concave lens
d) Astigmation	iv) Convex lens

• A. a - iii, b - iv, c- i, d -ii
• B. a - iv, b - iii, c -i, d - ii
• C. a - i, b - ii, c - iii, d - iv
• D. a - ii, b - iv, c -i, d - iii

Answer 1

The correct option is A a - iii, b - iv, c- i, d -ii

Myopia is inability to see distant objects as parallel rays from distant objects converge to a point in front of retina due to increased power of eye lens.Hence it is corrected by a concave lens of negative power to decrease net power.

Hyper metropia is inability to see near objects as diverging rays from near objects can not be converged to retina due to decreased power of eye lens.Hence a convex lens of positive power is used to increase power.

Presbyopia is caused by changes in the lens inside the eye. As people age, the lens becomes harder and less elastic, making it more difficult for the eye to focus on close objects.It is corrected by bifocal lenses.

Astigmatism is a type of refractive error in which the eye does not focus light evenly on the retina. It can be corrected by cylindrical lenses.